I like QSFS (QSUD?) because it's a decent oil AND is one of the least expensive oils I can get for my vehicles. (Used to be Supertech).
Having said that.... I have no idea how some of you guys are "hearing" an oil runs "quieter". ????? Seeing that this site thrives on "Data".... I'm wondering how one goes about listening for this type of thing?? Do you use a decibel meter?
Seems overly subjective to me.